Electron tube and socket



sept, 13; 1960 Filed March 8. 1955 J. A. MCCULLOUGH ET AL ELECTRON TUBE AND SOCKET 3 Sheets-Sheet 1 ATToa/EY l Sept. 13, 1960 Filed March 8, 1955 J. A. MCCULLOUGH ET AL ELECTRON TUBE AND SOCKET ATTORNEY Gear Pa 3 Sheeis-Sheet 2 INVENTORS Sept. 13, 1960 Filed March 8, 1955 J. A. MCCULLOUGH ETAL ELECTRON TUBE AND SOCKET 3 Sheets-Sheet 5 IN VLH TRS/7 Jack A. ME Ca ou George F. W/nderg//c Pau/ D. W/Y//ams TTOR/VE Y United States Patent ELECTRON TUBE AND SOCKET Jack A. McCullough, Millbrae, George F. Wunderlich, Burlingame, and Paul D. Williams, Menlo Park, Calif., assignors to Eitel-McCullough, Inc., San Bruno, Calif., a corporation of California Filed Mar. 8, 1955, Ser. No. 492,892

14 Claims. (Cl. 313-49) Our invention relates to electron tubes, and more particularly to such tubes having an improved ceramic envelope construction and socketing arrangement.

It is among the objects of our invention to provide an improved tube envelope structure comprising ceramic and metal rings assembled in stacked relationship.

Another object is to provide such a tube in which the metal rings are sandwiched between the ceramic bodies and function both as electrode anchor supports and as electrode terminal rings.

Another object is to provide a tube structure which may be fabricated by improved assembly techniques.

A further object is to provide an improved terminal arrangement Iand socketing structure which prevents the development of high resistance paths in tube circuits embodying our invention.

The invention possesses other objects and features of advantages, some of which, with the foregoing, will be set forth in the following description of our invention. It is to be understood that we do not limit ourselves to this disclosure of species of our invention, `as we may adopt variant embodiments thereof within the scope of the claims.

Referring to the drawings:

Figure 1 is 4a vertical sectional view of our improved tube; and

Figure 2 is a side view of the same.

Figure 3 is a side view, partly in section and partly in elevation, showing the tube inserted in its socket; and

Figure 4 is a top view of the socket.

Referring iirst to Figures 1 and 2, our improved tube is illustrated as ya tetrode in the power tube category having an anode dissipation rating of, say, l5() watts. The evacuated envelope is of generally cylindrical shape having a side wall comprising a stack of five ceramic rings 2, 3, 4, 6 and 7 with four flat metal rings 8, 9, 11 and 12 sandwiched therebetween. The ceramic is preferably a highly refractory body, such as alumina, the ceramic rings being metalized at both ends by a suitable metalizing procedure such as the molybdenum-manganese powder sintering process. The interposed metal rings are quite thin, say about .020 inch thick, and are of good electrical conductivity such as copper. These sandwiched parts are brazed together using high temperature brazing alloys such as copper-gold or the like.

The metallic bonds at the brazed joints form strong mechanical connections and also provide vacuum-tight seals so that the cylindrical side wall of the tube envelope is a solid impervious cylinder of rugged construction. The sandwiched metal rings in the side wall provide the desired lead-in conductors through the envelope, which rings perform the dual function of electrode anchoring supports and terminal members. Ceramic rings 2, 3, and 4 may conveniently be of the same size, but the upper ring 7 is preferably longer to provide more insulation between the anode and screen gn'd terminal.

External anode 13 is of metal such as copper, preferably cup-shaped, and forms the upper portion of the and the iinal seal is made by brazing together the registering edges of the anges at metallic bond 17. Anode 13 also preferably carries the exhaust tubulation 18 and a suitable finned cooler 19.

Other electrodes in the envelope, including cathode 21, control grid 22, and screen grid 23, are preferably coaxial electrodes projecting upwardly into anode 13. Cathode 21 is preferably of the oxide coated type, and grids 22 and 23 `are of conventional wire cage construction. All of these electrodes derive their support from the metal side wall rings. Thus, screen grid 23 is mounted on a tubular support 24 connected to upper ring 12; control grid 22 is mounted on a similar support 26 connected to ring 11; and cathode skirt 27 is mounted on tubular support 28 connected to ring 9. All these electrode supports are preferably formed integrally with the associated side wall rings so that these parts may be stamped or drawn as unitary structures from sheet metal. The tubular shape of the supports, together with the outturned base ilanges which form the side wall rings, provide an accurate mounting arrangement and rugged supports for the electrodes.

A suitable heater is provided for the cathode, preferably comprising a heater coil 29 having one end connected to a center rod 31 and the other end to a side rod 32. The latter is anchored to a conically shaped support 33 formed as part of the lower side wall ring 8. Center rod 31 has an enlarged lower portion extending through .and brazed to a conically shaped lower wall 34 of the envelope, which wall is a disk-like metal part brazed -at the periphery to the metalized end of lower ceramic ring 2.

An important feature of our invention has to do with the terminals on the envelope and an improved socketing arrangement. As shown in Figure 1, the side wall rings provide the electrode terminals, which terminals lie in spaced horizontal planes. The term electrode is used in its broad sense herein, and includes any tube element connected to a voltage source or having a potential differing from that of another element. Ring 12 comprises the screen grid terminal, ring 11 the control grid terminal, ring 9 the cathode terminal, and ring 8 a heater terminal. The metal bottom wall structure serves as the other hea-ter terminal. As best shown in Figure 2, we provide radially extending contacts 36 on the terminal rings, the contacts being arranged one above the other in a vertical row. These contacts are preferably formed as integral tabs on the terminal rings. A single row of such contact tabs may be provided, but to give optimum contact surface we preferably provide a series of contacts spaced circumferentially about the envelope, the contacts of the several terminal rings being disposed in vertical rows with spaces therebetween.

Our improved socketing apparatus for the tube is illustrated in Figures 3 and 4. The socket is a cup-shaped device having a recess into which the envelope is insertable. Rows of contacts 37 are provided in the socket complementary to those on the tube and engageable with the terminal contacts 36 upon rotation of the tube envelope; in other words, the socket contacts 37 are arranged to lie in the spaces between the rows of terminal contacts 36 when lthe envelope is inserted into the socket. When the envelope is fully inserted and rotated a certain distance, the terminal contacts 36 are shifted to positions under the socket contacts 37 The body of the socket may be of any suitable insulating material and is preferably made up of a lower cupshaped piece 38 together with a series of three wall rings 39 which serve as spacers for metal rings 41. The latter may be secured in place by brazing or in any other suitable manner to provide a unitary socket structure. Socket contacts 37 are formed as an integral part of the metal rings 41, the latter also having integral terminal lugs 42.

Means are also provided for guiding the tube envelope into the socket, preferably comprising a guide pin 43 projecting from lower ceramic ring Z and engageable with a Vertical indexing groove 44 in the socket recess. When the pin is in the vertical portion of groove 44, the rows of terminal contacts 36 lie in the spaces between the rows of socket contacts 37. A horizontal portion 46 of the guide groove allows the tube envelope to be rotated to engage the contacts.

Spring means are further provided in the socket for pressing the contacts together in the engaged position. This preferably comprises a spring pressed pin 47 in the base of the socket and centrally located to bear against the bottom wall structure of the envelope. Such pin also serves as a socket contact terminal for the heater.

A serious disadvantage of tube and socketing structures in the past has been the prevalence of poor tube-to-socket contacts which develop high resistance paths in tube circuits, resulting in deterioration in the performance of electronic equipments. This comes about on account of inadequate contact areas and insuiiicient gripping at the contact surfaces. We have overcome this problem by providing a large total contact area for each electrode terminal, namely, the sum of the areas of the contact tabs 36 disposed about each terminal ring. Also, since the tube and socket contacts move into wiping engagement, there is provided a desirable cleaning action which insures a close intimate engagement of the surfaces. And lastly, the upward spring pressure insures a tight surfaceto-surface engagement.

We claim:

l. An electron tube comprising a generally cylindrical envelope, electrodes in the envelope, electrode terminals on the envelope arranged in spaced horizontal planes, each terminal comprising a radially extendingexternal contact tab, the contact tabs of the several terminals being disposed in a vertical row, and a plurality of coaxial tubular supports for said electrodes each attached to a different one of said terminals within the envelope.

2. An electron ltube comprising a generally cylindrical envelope, electrodes in the envelope, electrode terminals on the envelope arranged in spaced horizontal planes, each terminal comprising a series of radially extending external contacts spaced circumferentially about the envelope, said contacts of the several terminals being disposed in vertical rows with spaces therebetween, and a plurality of coaxial tubular supports for said electrodes each attached to a different one of said terminals Within the envelope.

3. An electron tube comprising a generally cylindrical envelope having a side wall comprising a stack of metalized ceramic rings with flat metal rings sandwiched between the ceramic rings, metallic bonds uniting said ceramic and metal rings, electrodes in the envelope, supports for the electrodes extending from the metal rings, said metal rings providing electrode terminals, each terminal ring having an outwardly extending contact tab, the contact tabs of the several terminal rings being disposed in a vertical row.

4. An electron tube comprising a generally cylindrical envelope having a side wall comprising a stack of metalized ceramic rings with dat metal rings sandwiched between the ceramic rings, metallic bonds uniting said ceramic and metal rings, electrodes in the envelope, supports for the electrodes extending from the metal rings, said metal rings providing electrode terminals, each terminal ring comprising a series of outwardly extending contact tabs spaced circumferentially about the envelope, the contact tabs of the several terminal rings being disposed in vertical rows with spaces therebetween.

5. An electron tube comprising a generally cylindrical envelope having a side Wall comprising a stack of metalized ceramic rings with diat metal rings sandwiched between the ceramic rings, metallic bonds uniting said ceramic and metal rings, ran external anode forming the upper portion of the envelope and supported on the upper ceramic ring of the side wall stack, other electrodes in the envelope coaxial with the anode, and supports for the last mentioned electrodes extending from the metal rings, said metal rings providing electrode terminals, each terminal ring having an outwardly extending contact tab, the contact tabs of the several terminal rings being disposed in a vertical row.

6. An electron tube comprising a generally cylindrical envelope having a side wall comprising a stack of metalized ceramic rings with flat metal rings sandwiched between the ceramic rings, metallic bonds uniting said ceramic and metal rings, an external anode forming the upper portion of the envelope and supported on the upper ceramic ring of the side wall stack, registering metal ilanges on the anode and said upper ceramic ring, a metallic bond uniting said flanges, other electrodes in the envelope coaxial with the anode, and supports for the last mentioned electrodes extending from the metal rings, said metal rings providing electrode terminals, each terminal ring having an outwardly extending contact tab, the contact tabs of the several terminal rings being disposed in a vertical row.

7. An electron tube comprising a generally cylindrical envelope having a side wall comprising a stack of metalized ceramic rings with flat metal rings sandwiched between the ceramic rings, metallic bonds uniting said ceramic and metal rings, an external anode forming the upper portion of the envelope and supported on the upper ceramic ring of the side wall stack, other electrodes in the envelope coaxial with the anode, and a plurality of coaxial tubular supports `for the last mentioned electrodes each integrally formed with a different one of said at metal rings and extending upwardly from the metal rings, said metal rings providing electrode terminals, each terminal ring having an outwardly extending contact tab, the contact'tabs ofthe several terminal rings being disposed in a vertical row.

8. An electron tube apparatus comprising a tube having a generally cylindrical envelope, electrodes in the envelope, electrode terminals permanently fixed to the envelope and arranged in spaced horizontal planes, each terminal comprising a radially extending metal contact tab, the Contact tabs of the several terminals being disposed in a vertical row, a socket having a recess into which the tube envelope is insertable, a vertical row of contacts in the socket engageable with said terminal tabs upon rotation of the envelope, and a plurality of coaxial tubular supports for said electrodes each attached to a different one of said terminals within the envelope.

9. An electron tube apparatus comprising a tube having a generally cylindrical envelope, electrodes in the envelope, electrode terminals permanently iixed to the envelope and arranged in spaced horizontal planes, each terminal comprising a radially extending metal contact tab, the contact tabs of the several terminals being disposed in a vertical row, a socket having a recess into which the tube envelope is insertable, a vertical row of each terminal comprising a series of radially extending metal contacts spaced circumferentially about the envelope, said contacts of the several terminals being disposed in vertical rows with spaces therebetween, a socket having a recess into which the tube envelope is insertable, and vertical rows of contacts in the socket arranged to lie in the spaces between the rows of terminal contacts when the envelope is inserted and engageable with said terminal contacts upon rotation of the envelope.

11. An electron tube apparatus comprising a tube having a generally cylindrical envelope, electrodes in the envelope, electrode terminals permanently fixed to the envelope and arranged in spaced horizontal planes, each terminal comprising a series of radially extending metal contacts spaced circumferentially about the envelope, said contacts of the several terminals being disposed in vertical rows with spaces therebetween, a socket having a recess into which the tube envelope is insertable, vertical rows of contacts in the socket arranged to lie in the spaces between the rows of terminal contacts when the envelope is inserted and engageable with said terminal contacts upon rotation of the envelope, and means for guiding the envelope during insertion into said socket.

12. An electron tube apparatus comprising a tube having a generally cylindrical envelope, electrodes in the envelope, electrode terminals on the envelope arranged in spaced horizontal planes, each terminal comprising a series of radially extending metal contacts spaced circumferentially about and permanently xed to the envelope, said contacts of the several terminals being disposed in vertical rows with spaces therebetween, a socket having a recess into which the tube envelope is insert- `able, vertical rows of contacts in the socket arranged to lie in the spaces between the rows of terminal contacts when the envelope is inserted and engageable with said terminal contacts upon rotation of the envelope, means for guiding the envelope during insertion into said socket, and spring means in the socket pressing said contacts together in the engaged position.

13. An electron tube -apparatus comprising a tube having a generally cylindrical envelope, electrode terminals permanently iixed to the envelope and arranged in spaced horizontal planes, each termin-al comprising a series of radially extending metal contacts spaced circumferentially about the envelope, said contacts of the several terminals Ibeing disposed in vertical rows with spaces therebetween, a socket having a recess into which the tube envelope is insertable, vertical rows of contacts in the socket 'arranged to lie in the spaces between the rows of terminal contacts when the envelope is inserted and engageable with said terminal contacts upon rotation of the envelope, and means for guiding the envelope during insertion into the socket, said means comprising a groove and a cooperating pin one on said envelope and the other on said socket and adapted to enter into engagement before the iirst of said terminals on said envelope engages the first of said contacts of said socket.

14. An electron tube apparatus comprising a tube having a generally cylindrical envelope, electrode terminals permanently fixed to the envelope and arranged in spaced horizontal planes, each terminal comprising a series of radially extending metal contacts spaced circlnnferentially about the envelope, said contacts of the several terminals being disposed in vertical rows with spaces therebetween, a socket having a recess into which the tube envelope is insertable, vertical rows of contacts in the socket arranged to lie in the spaces between the rows of terminal contacts when the envelope is inserted and engageable with said terminal contacts upon rotation of the envelope, and means for guiding the envelope during insertion into the socket, said means comprising a pin extending radially outwardly from the lower extremity of said envelope and a groove in the inner surface of said recess of said socket, said groove having an axially extending portion terminating in a circumferentially extending portion, said pin being adapted to cooperatively engage said groove before the first of said terminals engages the rst of said contacts of said socket, whereby said envelope is guided into said socket by said axial portion a-nd locked in said socket by said circumferential portion of said groove.

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